1. Field of the Invention
This invention relates to relatively small fluid flows and, more particularly, to restrictor apparatus for restricting relatively small fluid flows.
2. Description of the Prior Art
U.S. Pat. No. 2,247,227 (Findley) discloses valve apparatus for varying the flow of hot water through a heater core or a vehicle. The valve includes a metering disk having a variably configured opening in the disk. The flow rate varies with the location of the variable sized opening relative to the outlet conduit. As the metering disc is adjusted, more or less of the variable sized opening is exposed to the outlet conduit, thus varying the flow rate of the fluid through the valve apparatus.
U.S. Pat. No. 2,531,480 (Sparklin et al) discloses a variable drip valve which utilizes a metering disk with a variable sizes slot in the disk. The output flow rate of the valve varies with the location of the slot relative to the output conduit of the valve.
U.S. Pat. No. 2,572,950 (Rider) discloses a control valve which also utilizes a rotatable disk with a variable sized slot in the disk. Rotation of the disk varies the location of the slot relative to the input and output conduits of the valve apparatus.
U.S. Pat. No. 2,911,008 (Du Bois) discloses flow control apparatus in which a flow restrictor element includes a relatively movable element and a pair of variable capacity slots. Dam elements, fixed in place, are used to control the fluid flow as the elements are moved relative to each other.
U.S. Pat. No. 2,999,512 (Barkow) discloses valve apparatus in which a metering disk is disposed in the valve body. The metering disk includes a variable sized crescent shaped opening extending through the disk. A valve is movable relative to the metering disk, and movement of the valve controls movement of the flow of fluid through the metering disk. The metering disk is adjustable relative to the valve so that the flow varies through the opening in the metering disk.
U.S. Pat. No. 3,334,861 (Westbrook) discloses a valve in which relative rotation between two members varies the flow of fluid through the members. The members include spiral slots extending through the members and the alignment of the members varies the flow of fluid through the spiral slots.
U.S. Pat. No. 4,477,404 (Stoll et al) discloses a process for producing grooved plates. The purpose of the grooved plates is to vary the flow of fluid in relation to the size of the grooves in the plates.
U.S. Pat. No. 4,946,134 (Orlandi) discloses a pair of ceramic disks usable in a faucet. The disks include variable orifices through them, and the alignment of the disks relative to each other determines the flow of fluid through them.